When many MiNiFi agents running on the edge, it may not be possible to manually stop, edit the config.yml and then restart every one every time their configuration needs to change. The Config Change Coordinator and its Ingestors were designed to automatically redeploy in response to a configuration update.

The Config Change Ingestors are the means by which the agent is notified of a potential new configuration. Currently there are three:

FileChangeIngestor

RestChangeIngestor

PullHttpChangeIngestor

After a new configuration has been pulled/received the Ingestors use a Differentiator in order to determine if the currently running config is different than the new config. Which Differentiator is used, is configurable for each Ingestor. Currently there is only one Differentiator:

WholeConfigDifferentiator: Compares the entire new config with the currently running one, byte for byte.

After a new config is determined to be new, the MiNiFi agent will attempt to restart. The bootstrap first saves the old config into a swap file. The bootstrap monitors the agent as it restarts and if it fails it will roll back to the old config. If it succeeds then the swap file will be deleted and the agent will start processing using the new config.

Note: Data left in connections when the agent attempts to restart will either be mapped to a connection with the same ID in the new config, or orphaned and deleted.

The configuration for Warm-Redeploy is done in the bootstrap.conf and primarily revolve
around the Config Change Ingestors. The configuration in the bootstrap.conf is done using the
"nifi.minifi.notifier.ingestors" key followed by the full path name of the desired
Ingestor implementation to run. Use a comma separated list to define more than one Ingestor
implementation. For example: